diff options
Diffstat (limited to '')
-rw-r--r-- | src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp b/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp new file mode 100644 index 00000000..2e61c071 --- /dev/null +++ b/src/VBox/Runtime/generic/RTMpGetArraySize-generic.cpp @@ -0,0 +1,72 @@ +/* $Id: RTMpGetArraySize-generic.cpp $ */ +/** @file + * IPRT - Multiprocessor, Generic RTMpGetArraySize. + */ + +/* + * Copyright (C) 2010-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/mp.h> +#include "internal/iprt.h" + +#include <iprt/asm.h> +#include <iprt/cpuset.h> + + +RTDECL(uint32_t) RTMpGetArraySize(void) +{ + /* + * Cache the result here. This whole point of this function is that it + * will always return the same value, so that should be safe. + * + * Note! Because RTCPUSET may be to small to represent all the CPUs, we + * check with RTMpGetCount() as well. + */ + static uint32_t s_cMaxCpus = 0; + uint32_t cCpus = s_cMaxCpus; + if (RT_UNLIKELY(cCpus == 0)) + { + RTCPUSET CpuSet; + uint32_t cCpus1 = RTCpuLastIndex(RTMpGetSet(&CpuSet)) + 1; + uint32_t cCpus2 = RTMpGetCount(); + cCpus = RT_MAX(cCpus1, cCpus2); + ASMAtomicCmpXchgU32(&s_cMaxCpus, cCpus, 0); + return cCpus; + } + return s_cMaxCpus; + +} +RT_EXPORT_SYMBOL(RTMpGetArraySize); + |